(19)
(11) EP 0 816 579 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.04.1998 Bulletin 1998/14

(43) Date of publication A2:
07.01.1998 Bulletin 1998/02

(21) Application number: 97110488.0

(22) Date of filing: 26.06.1997
(51) International Patent Classification (IPC)6: E02F 9/26, E02F 3/43, E02F 9/22
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

(30) Priority: 26.06.1996 JP 166378/96

(71) Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Chiyoda-ku, Tokyo (JP)

(72) Inventors:
  • Fujishima, Kazuo, c/o Hitachikenki Tsukuba-ryo
    Niihari-gun, Ibaraki-ken (JP)
  • Watanabe, Hiroshi
    Ushiku-shi, Ibaraki-ken (JP)
  • Haga, Masakazu
    Niihari-gun, Ibaraki-ken (JP)
  • Nakagawa, Takashi, c/o Hitachikenki Tsukuba-ryo
    Niihari-gun, Ibaraki-ken (JP)

(74) Representative: Beetz & Partner Patentanwälte 
Steinsdorfstrasse 10
80538 München
80538 München (DE)

   


(54) Front control system for construction machine and oil temperature indicator


(57) In an oil temperature detecting/calculating portion 9p, threshold values T1, T2 are set beforehand to divide a range of oil temperature into a first oil temperature range a representing the lowest level, a second oil temperature range b representing a relatively low level, and a third oil temperature range c representing a normal level. The calculating portion 9p executes an alarm control process for making the alarm lamp 14 light up continuously when the detected oil temperature is in the first oil temperature range a, making the alarm lamp 14 blink when it is in the second oil temperature range b, and making the alarm lamp 14 turn out when it is in the third oil temperature range c. This enables a front control system for a construction machine to perform front control accurately and safely even when the temperature of hydraulic oil is low.






Search report